Handheld and robotic surgical systems have been used in minimally invasive medical procedures. While handheld systems typically included a handle assembly and an elongated body portion, some robotic surgical systems included a console supporting a robot arm. Nonetheless, both handheld and robotic surgical systems included at least one end effector such as a forceps or a grasping tool that was mounted to the robot arm or the elongated body portion for performing a medical procedure. During a medical procedure, the end effector was inserted into a small incision (via a cannula) or a natural orifice of a patient to position the end effector at a work site within the body of the patient. The end effectors were designed to be moveable through multiple degrees of motion in order to navigate in the work site and/or manipulate tissue therein.
As demand for smaller end effectors increased, device manufacturers continued to develop end effectors such as grasping and cutting end effectors having smaller cross-sectional areas. These smaller cross-sectional areas reduced the total force that could be applied between the jaws of the end effector. However, the need for sufficient mechanical advantage for all end effector configurations, regardless of size and/or motion, continued to factor into end effector design.
Thus, there is a need for end effectors that are able to provide higher forces between two jaws of the end effectors while one or both of the two jaw move between various positions and/or conditions.